Feeding mechanism for sewing machines



Jan. 19, 1932. c. THOBROE ET AL FEEDING MECHANISM FOR SEWING MACHINES 2 Sheets-Sheet 1 Filed Oct. 3, 1927 fi mm hm Jan. 19, 1932. c. THOBRQE ET AL 1,841,859

FEEDING MECHANISM FOR SEWING MACHINES Filed Oct. 3. 1927 2 Sheet-Sheet 2 Patented Jan. 19, 1932 UNITED STATES PATENT OFFICE CARL 'I'HOBROE AND FRIEDRICH LUTZ, OF STUTTGAJRT, GERMANY, ASSIGNORS TO UNION SPECIAL MASCHINENFABRIK, G. M. B. H., O]? STUTTGART, GERMANY FEEDING MECHANISM FOR SEWING MACHINES Application filed October 3, 1927, Serial No. 223,677 and in Germany December 11, 1926.

. The invention relates to new and useful improvements in feeding mechanisms for sewing machines, and more particgularly to 'an auxiliary feeding mechanism which is used jsfin, conjunction with amain feeding mechanism for aiding in feeding the materials.

An object of the invention is to provide an auxiliary feeding mechanism which in cludes cooperating rollers which are intermittently operated in timing with the feed dog of the main feeding mechanism wherein said rollers and actuating mechanism there- 'for are mounted on a bracket capable of being attached to the bed of the machine containing the main feeding mechanism.

A further object of the invention is to provide an auxiliary feeding mechanism of the above type whereinthe upper feeding roller is mounted directly at the end of a lever supported on the bracket, which lever is spring pressed so as to yieldingly hold the rollers in cooperative engagement with each other.

A still further object of the invention is to provide a device of the above character where- 5 in the hand operated lever is provided with a cam adapted to be brought into engagement with the lever supporting the feed roller for raising the feed roller from the material.

These and other objects will in part be fully disclosed. v

In the drawings which show by way of illustration one embodiment of the invention Figure 1 is a rear view of a sewing machine frame showing the improved auxiliary feeding mechanism as applied thereto;

Fig. 2 is a vertical sectional view through iar feeding mechanism in end elevation;

Fig. 3 is a sectional view through the bed showing the auxiliary feedin mechanism from the opposite end from t at shown in Figure 2;

Fig. 4 is a detail showingthe feedrocker and the means carriedthereby for actuating the auxiliary feeding mechanism.

The invention is shown as applied to a sewing machine having the usual form" of frame 59 with an overhanging arm in which the needle obvious and will in part be hereinafter more a the machine by suitable screws a.

a portion of the machine showing the auxilbar reciprocates. The bed of the machine is indicated in Figure 2 at e. Mounted on the bed of the (machine is a work support 1; provided with a throat plate 2 through which the feed dog 0 of the feeding mechanism operates. A presser foot 3 cooperates with the feed dog in its normal feeding operation. The feed dog is carried by a feed bar 7 which is pivoted at r to a feed rocker s. The feed rockers is in turn pivotally supported by a rod t mounted in bearing lugs u, u. The feed bar is raised and lowered by an eccentric n carried by the main actuating shaft 2). These I are the ordinary parts of the feeding mechanism disposed in the usual manner in a sewing machine and further detailed description thereof is not thought necessary.

The present invention is directed to an auxiliary feeding mechanism which is associated with the main feeding mechanism. This auxiliary feeding mechanism includes two cooperating feeding rollers' 0 and I). These feeding rollers are directly in rear of the main feed dog 0, and the material passing beneath the presser foot and fed across the work support by the feed dog passes between these feeding rollers. These feeding rollers are located just in rear of the work support 1. Both the feeding rollers and the actuating mechanism therefor are mounted on a bracket a. This bracket a is provided with depending lugs, and also horizontally extending lugs which are secured'to the bed plate 6 of serves as a means for rigidly securing the bracket a to the'bed of the machine.

The bracket a is provided with three bear ings 4, 5 and 6 in which is mounted a shaftsupporting the lower feeding roller b. The bracket a at the left hand end thereof, as viewed in Fig. 1, isrprovided with upstanding members which are joined so'as to pro vide an auxiliary bracket or standard 7 Lo- ,cated between the spaced me nbers of this auxiliary bracket 7 is the clutch drum (1. The

clutch drum is rigidl connected to the shaftcarrying the roller The clutch drum is This sis

turned step by step by a clutch disk 8 between which and the drum are suitable clutchde:

vices which will engage the drum whenithe z;

7 disk 8 is turned in one direction, and which will be freed from engagement with the drum when the disk is turned in the opposite direction.

I A suitable'clutching device is provided for preventing retro ra emovement of the shaft carrying t e roller b. This clutch mechanism is the usual type and has not been shown in the drawings. The disk 8 is oscillated by means of a link 3 Mounted on the feed rocker is an upstanding arm m which passes up through a slot in the work support. This arm a: is provided with a segmental slot 0:. A ball headed stud is adj ustably mount-. ed in this segmental slot or and the head 2 of the link y engages the said ball stud. The other end of the link y is provided with a head which engages a ball stud on an arm ex"- tending from the disk 8. When the feed rocker oscillates it will turn the disk 8 through a step movement and this through the ratchet mechanism will rotate the feeding roller I) through a step movement. Thus it is that the lower feeding roller 6 is rotated intermittently in timin movements of the feed 0g 0. Both the feed dog and the feeding roller are actuated from the one common feed rocker and this is what brings about a proper synchronism in the movements of the feed dog and the feed roller. The surface of the feed roller 1) is fluted. The surface of the feed roller 0 is also fluted, and the fluted surfaces interengage one an other so that the rotation of the lower feeding roller will cause the upper feeding roller to rotate in unison therewith,

The upper feed roller 0 is freely mounted on a shaft carried by a yoke 9. This yokq 9 is pivoted at 10 to theend of a lever f. The lever f is horizontal and is pivoted at g to the auxiliary bracket which projects upwardlgifrom the main bracket a. A spring Z is ed to the bracket and bears at its outer end against a lug Z on the under face of the lever f. An adjusting screw Z bears against the spring I and serves as a means for varying the tension of the spring. This spring raises the left hand end of the lever f, as viewed in Figpre 1, and this will yieldingly depress the rig t hand end and hold the roller 0 yieldingly'in engagement with the fabric passing be tween t e rollers of the auxiliary feeding mechanism. A treadle may be connected to the end n of the lever f for raising the roller 0 from engagement wtih the material.

A hand lever is also provided for raising the roller 0 from the material. This lever is indicated at h in the drawing. The lever is the position shown in Fig. 1 with the hand lever against the stop m at the left of the lever then the leverf carrying the roller is rewith the feeding leased and the spring can force the roller into engagement with the material. When the lever h is turned in a clockwise direction so as to engage the stop m at the right thereof then the cam portion In on the hand lever will engage the lug f on the lever f raising the roller 0 from engagement with the material From the above it will be apparent that a very simple auxiliary feed-ing mechanism often referred to as 'a puller has been provided which may be used in conjunction with an ordinary flat bed sewing machine to aid in the feeding of the materials. This is particularly useful when stitching heavy materials, such as awnings, tents, automobile tops, and in sewing a rubber band under tension. The auxiliary feeding mechanism is all mounted on a bracket as a unit, and this bracket with its feeding mechanism is in turn mounted on the bed of the machine to which it is to be attached. After the mounting of the bracket all that is necessary is to connect the link which actuates the auxiliary feeding mechanism toan arm on the feed rocker which moves the feed dog back and forth.

It is true that afeed rocker having the arm for actuating the auxiliary feeding mechanism would have to be substituted for the usual feed rocker. With this very slight change, which any mechanic may accomplish in a ver short time an ordinar sewin machine having a four-motion feed dog may be equipped with an auxiliary feeding mechanism in the nature of a puller.

It is obvious that minor changes in the details of 1 construction and arrangement of parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus fully described our invention, what we claim as new and desire to secure by Letters Patent, is:-

1. A sewing machine including in combination a bed plate, a work support, a main feeding mechanism including a feed dog,

means for moving said feed dog back'and forth, an auxiliary feeding mechanism including coo era'ting upper and lower feed ing rollers, evices for intermittently actuating said feeding rollers from the main feeding mechanism, a bracket, means for attaching said bracket directly to the bed plate, a shaft carrying the lower feeding roller, said bracket having bearings at each side of the feeding roller for said shaft.

2; A sewing machine including in combination a bed plate, a work support, a main feeding mechanism, including a feed dog, a feed bar carrying said feed dog, a feed rocker to which said feed bar is connected, means for raising and lowering the feed dog, an auxiliary feeding mechanism including cooperating upper and lower feeding rollers, a bracket rigidly secured to the bed of the machine, a shaft on which the "lower feeding roller is mounted, said bracket having bearin s at each side of the'feeding roller for said s aft, a ratchet mechanism mounted on said shaft for actuating the same, said feed rocker having an upwardly projecting arm and a link connecting said arm to said ratchet mechanism for actuating the same.

3. A sewing machine including in combination a bed plate, a'worki support, a main feeding mechanism including a feed dog,

-means for moving said feed dog back and upper feeding roller, and means operating on said lever for yieldingly holdingsaid feeding rollers in engagement with each other.

.dog, a

4. A sewing machine including in combination a bed plate, a work support, a main feeding mechanism including a feed bar, a feed dog carried thereby, a feed rocker to which said feed bar is connected, means for raising and lowering the feed dog, an auxiliary feeding mechanism including cooperating upper a bracket having a portion overliing the-bed plate and a portion engaging t e rear face thereof, screws for attaching said bracket to said bed plate, said bracket having upwardly extending spaced arms, a shaft mounted therein, a lower feed roller mounted on said shaft, means operated from said feed rocker v for intermittently rotating said shaft, a

presser roller cooperating with said feed roller, a lever mounted on said bracket, a yoke supported by said lever in which said presser roller is mounted, a spring operating on said lever for yieldingly depressing said presser roller, and means carried by said racket and operating on said lever for raisin said presser roller.

n testimony whereof, we affix our signatures.

1 CARL THOBROE.

FRIEDRICH LUTZ,

and lower feeding rollers, a bracket rigidly secured to the bed of the machine, a shaft on which the lower feeding roller is mounted, said bracket having bearings at each side of the feeding roller for said shaft, a ratchet mechanism mpunted on said shaft for actuating the same, said feed rocker having an upwardly projecting arm and a link connecting said arm to-s'aid ratchet mechanism for actuating the same, a lever mounted on said bracket and supporting said upper feeding roller, and means operating on said lever for yieldingly holding said feeding rollers in engagement with each other.

5. A sewin machine including in combination a bed plate, a work support, a main feeding mechanism including a main feed feed rocker and carrying said feed do a bracket having a portion overlying the plate and a portio n enga g the rear face thereof, screws for attachm said bracket to said bed late,- said bracket aving upwardexten ing spaced arms, a shaft mounted t erein, a lower feed roller mounted on said shaft, means operated from said feed rocker for intermittently rotating said shaft, a presser roller cooperat' with said feed roller, and means carried y said bracket for supporting said presser roller.

6. A sewin bination a plate, a work support, a main feeding mechanism including a main feed dog, a feedirocker, a feed bar connected to the feed rocker and carrying said feed dog,

ed rocker, a feed bar connected to the,

machine includingin com- 

